The present invention relates to communication systems, and more particularly to a method and apparatus for communicating computer data provided according to a first data protocol (e.g., the Internet protocol) over a digital television broadcast network which uses a second data protocol (e.g., MPEG2) to carry a plurality of data streams.
Communication systems may be described as being unidirectional or bidirectional in nature. Unidirectional systems include broadcast services such as radio and television. Bidirectional systems include telephone and computer networks.
It is expected that broadcast services, which currently use analog distribution schemes, will be transitioned to digital communication schemes. Presently, the most common way to encapsulate information for communication over a digital broadcast service is to use standards developed by the Moving Picture Experts Group (MPEG), and particularly the MPEG2 standard described in the International Standards Organization ISO/IEC 13818 standard.
The digitization of broadcast services will provide many benefits. Among these are digital television and, ultimately, high definition television (HDTV). The availability of digital broadcast services can also provide for the communication of other types of information, such as Internet access. Presently, the most common way to encapsulate such computer information is to use the Internet protocol (IP). This protocol is entirely different from the MPEG2 protocol used, for example, in digital television broadcasting.
It would be advantageous to provide Internet access via a subscription television service, such as cable or satellite television. It would be further advantageous to provide Internet access to users who do not own personal computers. Such access could be provided, for example, via their television sets. To date, most access via the Internet has been made by conventional analog telephone modems and integrated service digital networks (ISDN) which operate at higher speeds than standard telephone lines, but at significantly higher cost. One alternative to using conventional analog telephone modems and ISDN services is to access Internet services with modems that can operate on cable or satellite television networks. Such networks have much greater bandwidth than is provided by telephone lines, and can therefore be advantageously used for high speed Internet communications. Currently, most cable television (CATV) networks (and all television satellite networks) are one-way broadcast networks. Such networks only provide communication from a headend to a user, and not in the reverse direction. Although the industry is upgrading to two-way ("bidirectional") CATV networks at a high rate, more than one-half of the one-way networks presently in existence are expected to remain into the foreseeable future.
Thus, it would be further advantageous to provide a cable or satellite modem that is low in cost, in order to enable cable and satellite television operators to provide low cost, high speed Internet access to their customers. It would be still further advantageous to provide low cost Internet access to the vast population of cable and satellite television subscribers.
The present invention provides methods and apparatus having the aforementioned and other advantages.